When stating 'you seem' you're referring to the person you are talking to and expressing that they are giving the impression of or appear to be.

Here are some examples:

"You seem bored."
"You seem unhappy with the results."
"You seem eager to begin."
"You seem easy to get along with."
"You seem elated to hear the good news."
"You seem deeply in love."
"You seem afraid of roller coasters."
"You seem confused about the rules of the game."
"You seem embarrassed about what happened."
"You seem decisive about your choice."